Volcanic rock - ???

[GTR73]

Ok, number of questions:
Does it go good in an external canister as a biological media?
Do you need to soak it/wash it first whatever?
Is it better than ceramic noodles for externals?
It doesn't reach a saturation point for any reason and you can use indefinately?
Where can I get some? Landscapers?

Thanks  :D

[Monty]

I got some called scoria for my canister... was cheap as chips from the local landscaping supplies...

Cheers  :lol: